Genetic studies of autoimmunity and retrovirus expression in crosses of New Zealand black mice I. Xenotropic virus.

The relationship between expression of xenotropic virus and the development of autoimmunization was studied in the progeny of crosses between New Zealand Black (NZB) and SWR mice. The (F1 X SWR) and F2 progeny segregated into three phenotypes: high-virus, low-virus, and virus-negative; F1 and (F1 X NZB) progeny were always high-virus. Autoantibodies, immune deposit nephritis and lymphomas developed in the progeny of these crosses. The virological phenotype of the animal could be dissociated from the presence of either autoantibodies or nephritis. For example, mice that expressed titers of virus as high as the NZB parent failed to develop signs of autoimmunization, even up to 24 mo of age. By contrast, some (F1 X SWR) and F2 mice that expressed low titers of virus developed autoimmune disease. Furthermore, a proportion of virus-negative mice produced autoantibodies and were found to have typical immune deposit nephritis. No viral antigens could be detected in the renal lesions of such virus-negative animals. By contrast with the dissociation between expression of virus and occurrence of nephritis, the presence of antibodies to DNA correlated with the development of renal lesions. We conclude that the genes that determine the expression of infectious xenotropic virus in NZB mice segregate independently from those that are involved in the autoimmune disease of these animals.

Genetic studies of autoimmunity and retrovirus expression in crosses of New Zealand black mice. II. The viral envelope glycoprotein gp70.

The retroviral envelope glycoprotein, gp70 was measured in the serum of New Zealand Black (NZB) and SWR mice and the progeny of their crosses. The serum gp70 values segregated to "NZB-like" and "SWR-like" levels in these mice. A complex mechanism determined the inheritance of NZB-like serum gp70 levels. We found that the factors determining the expression of this retroviral protein were independent of the genes (Nzv-1 and Nzv-2) that determined the expression of infectious xenotropic virus. Autoimmune disease, including immune deposit nephritis could be dissociated from the degree of expression of serum gp70. By contrast, presence of circulating immune complexes and anti-DNA antibody did correlate with the development of nephritis in these crosses. A significant correlation was found between high grade expression of serum gp70 and the presence of lymphomas in these mice.

Generation of a monoclonal anti-GP70 antibody and characterization of its reactivity with various human cell lines and cells from leukemia-lymphoma patients.

Monoclonal anti GP-70 antibodies (BI) were generated in mice and used for screening of various malignant and non-malignant cell lines. The reactivity of these monoclonal antibodies was compared with that obtained with the polyclonal anti GP-70 antibody described in earlier studies [1-3]. The results indicated complete similarity in reactivity of both of the antibodies used. Furthermore, the reactivity of BI antibodies with cell samples obtained from a variety of leukemia and lymphoma patients and with peripheral blood samples from healthy blood donors was also very similar to the pattern of specificity described in earlier reports for the polyclonal preparation. From these studies we conclude that the monoclonal antibodies can substitute the polyclonal anti GP-70 antibodies in the diagnosis and subtyping of B-type leukemias and lymphomas.

Hepatitis c virus infection in employees of a large university hospital in Israel.

OBJECTIVE: To assess whether hospital work constitutes a risk factor for hepatitis C virus (HCV) infection among employees of a large hospital in Israel. DESIGN: Seroprevalence survey. SETTING: A 1,006-bed, tertiary-care university hospital in Jerusalem. PARTICIPANTS: All 5,444 employees (18-65 years old) were eligible; 4,287 (79%) participated in the survey. METHODS: Sera were tested for antibodies to HCV (anti-HCV) using a third-generation enzyme immunoassay. A third-generation strip immunoblot assay was used for confirmation. Participants were interviewed regarding their occupational history, and they completed a self-administered questionnaire covering history of non-occupational exposure to blood and country of birth. Other demographic information was obtained from the personnel department. Rates and odds ratios (ORs) were calculated, and multivariate logistic-regression analyses were performed to adjust for potential confounding variables. RESULTS: Anti-HCV was found in 0.9% of employees (37/4,287; 95% confidence interval, 0.6-1.1), ranging from 0.1% among those born in Israel to 5.7% among those born in Central Asia. After age, gender, social status, country of birth, and history of blood transfusion were controlled for in a logistic regression, occupational exposure to blood > or = 10 years was significantly associated with the presence of antibodies (OR, 2.6; P=.01). Presence of anti-HCV also was associated with country of birth (range: Israel OR, 1; West OR, 3.8 [P=.1]; Central Asia OR, 48.6 [P<.0001]) and history of blood transfusion (OR, 2.7; P=.01). No significant associations were found between anti-HCV and age, gender, social status, history of tattoo, acupuncture, current occupation, department, exposure to blood in current occupation, adherence to safety precautions, or history of percutaneous injury. The association with length of exposure was stronger (OR, 3.6; P=.01) when the same logistic regression was run excluding the outlier ethnic group of Central Asia. CONCLUSIONS: Hospital work does not seem to constitute a major risk factor for HCV infection in Israel today. A higher prevalence of anti-HCV among employees with longer versus shorter lengths of occupational exposure may be due to a cumulative effect of exposure over the years. Infection control efforts in recent years may have contributed to this association.

Monitoring of intraoperative heparinization in vascular surgery.

In 15 patients undergoing aortofemoral bypass, partial thromboplastin time (PTT) tests before and following intravenous administration of 75 U. per kilogram of heparin at zero, 30, 60, 90, and 120 minutes were determined for study of control of anticoagulant adequacy. The results demonstrate clearly that this amount provides excellent protection against thrombosis without bleeding complications. For intraoperative assay of heparin level effectiveness, the PTT test is advised. This test showed that a value of 250 percent of control still existed 75 minutes following the administration of heparin.

The haematologist as watchdog of community health by full blood count.

Although full blood counts (FBC) are among the most commonly performed laboratory tests, the contribution of routine FBCs to the diagnosis of new problems is controversial. This study represents a unique linkage of a consultant haematology team, reviewing all abnormal blood counts, to an organization providing ambulatory health care to 350,000 patients. The objective was to establish the underlying clinical disorders responsible for all abnormal FBCs during a 2-month period, and to estimate the impact of the haematology team on the diagnostic work-up and management of newly identified problems. 572 (2.55%) of the 22,454 FBCs were abnormal. Of these, 357 showed microcytosis, caused by iron deficiency (58%), thalassaemia minor (35%), inflammation (6%) or chronic renal failure (1%). The most common causes of normocytic anaemia (25 patients) were disseminated malignancy and acute blood loss; of macrocytosis (27 patients), chronic liver disease and cancer; of erythrocytosis (16 patients), chronic hypoxia; of thrombocytopaenia (48 patients), chronic liver disease and ITP; of thrombocytosis (47 patients), iron deficiency and inflammation; of leukopaenia or pancytopaenia (20 patients), cirrhosis and disseminated malignancy; and of leukocytosis (26 patients), chronic leukaemias in the elderly and infection in children. Major new haematological abnormalities were encountered in 0.24% of all blood counts, representing about one new diagnosis per day. Routine blood counts do contribute to the health care of a population. Screening for haematological disease through a central clinical laboratory covering a large high-risk ambulatory population offers a cost-effective way of searching for serious clinical problems, alerting the primary physicians of their existence, and offering advice in continued evaluation and problem management.

The effects of blood transfusions on PCR DNA typing at the CSF1P0, TP0X, TH01, D1S80, HLA-DQA1, LDLR, GYPA, HBGG, D7S8 and GC loci.

Pre-transfusion and post-transfusion blood samples from eight individuals were typed at 10 PCR amplified loci. In no case did the PCR DNA profile of the post-transfusion blood sample differ from that of the pre-transfusion profile.

Laboratory diagnosis of autoimmune cytopenias.

The past year's literature shows that little progress has been achieved in the laboratory diagnosis of autoimmune hemolytic anemia. The direct antiglobulin test is the only diagnostic test for autoimmune hemolytic anemia. Advantages of new techniques, such as the gel test, have to be determined. Today, cephalosporins are known to cause both drug-dependent and -independent autoantibodies. The diagnosis of idiopathic thrombocytopenic purpura is a clinical one. The new assays that measure antibodies against specific glycoproteins offer improved specificity. New laboratory advancements and accumulation of data on granulocytes' antigens and antibodies enabled us to recommend guidelines for the laboratory investigation of autoimmune neutropenia.

Posttransfusional hemolysis in recipients of glucose-6-phosphate dehydrogenase-deficient erythrocytes.

To test the hypothesis that transfusion of blood donated by individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency may result in a hemolytic reaction, we conducted a prospective longitudinal study in which 10 patients transfused with 1 unit of G6PD-deficient and 1 unit of normal red blood cells (RBC) were compared with 10 patients transfused with 2 units of age-matched normal RBC. We found that 24 h after transfusion serum bilirubin (mumol/l) in the recipients of G6PD-deficient RBC was significantly higher than in the recipients of normal RBC (36 +/- 14 vs. 18 +/- 5, respectively, p > 0.004). A parallel increase was found in the serum lactate dehydrogenase (LDH; IU/l) between the two groups (378 +/- 151 vs. 264 +/- 56, p < 0.001). The difference in serum bilirubin (26 +/- 10 vs. 15 +/- 5, p < 0.03) was still noted 48 h after transfusion, with only a marginal difference (p < 0.08) in LDH. We conclude that an immediate posttransfusional hemolytic reaction can occur in recipients of G6PD-deficient RBC and therefore suggest that the differential diagnosis of posttransfusional hemolysis, particularly in populations where G6PD deficiency is prevalent, includes transfusion of erythrocytes from G6PD-deficient donors.

The transcobalamins in polycythaemia vera.

The unsaturated B12 binding capacity (UBBC) of the serum and the binding capacity of each of the 3 vitamin B12 binders--the transcobalamins (TC) I, II and III were determined in 21 patients with polycythaemia vera (PV) during the course of the disease and following treatment, using the recently described charged cellulose filter technique. High serum UBBC due to elevated serum TCIII was found in all patients. TCI was moderately elevated in patients who had leucocytosis with a shift to the left. The changes in serum TCIII and UBBC correlated with the activity of the disease. Chemotherapy resulted in a decrease in TCIII and UBBC. The decrease in TCIII and UBBC folowing chemotherapy may be observed before a decrease in the haematocrit and the leucocyte count occurs. Activation of the disease may be assessed by the elevation of TCIII and UBBC. The onset of acute myeloblastic crisis in 1 patient was associated with a decrease in TCIII and TCI levels and a rise in serum TCII. The determination of TCIII and UBBC may be helpful in differentiating true from secondary polycythaemia.

EA rosette formation: a simple means to increase sensitivity of the antiglobulin test in patients with anti red cell antibodies.

Erythrocyte antibody (EA) rosette formation with the Fc-receptor on the K-562 erythro-myeloid cell line was employed for the detection of subagglutinating amounts of Ig molecules bound to red cells. The sensitivity of this method exceeds that of the conventional direct and indirect antiglobulin tests without any alteration of the incubation media or pretreatment of red cells. The increased sensitivity did not diminish the specificity of the test, which can detect IgG, IgM and complement as well. This method may demonstrate the presence of antibodies on red cells in patients with suspected autoimmune haemolytic anaemia and negative antiglobulin test.

Autoimmune hemolytic anemia in Gaucher's disease.

A 23-year-old Ashkenazi woman with Gaucher's disease developed Coombs-positive warm-type autoimmune hemolytic anemia. Treatment with high-dose steroids resulted in complete remission within 2 weeks. Study of an additional 72 patients with Gaucher's disease revealed another case of Coombs-positive warm-type autoimmune hemolytic anemia; other autoimmune disorders were found in 17 of these patients. The possible association of Coombs-positive hemolytic anemia and Gaucher's disease is discussed.